ABSTRACT
This chapter describes the synthesis and characterization of four types of degradable and de-cross-linkable polymers. The first type of polymer, poly(L-lactide-co-trimethylene carbonate), possess in-chain ester and carbonate groups and is prepared by copolymerization approach. The second type of polymer, polyacetal, has in-chain acetal groups and is synthesized by self-polyaddition of hydroxyalkyl vinyl ethers. The third type of polymer gains degradable and de-cross-linkable properties through dicyclopentadiene groups, which can undergo thermally reversible cleavage to form cyclopentadiene groups upon heating via the reversible Diels-Alder reaction. The fourth type of polymer, as quaternary ammonium-containing crosslinked networks, has thermally reversible de-cross-linking properties based on the dequaternization of quaternary ammoniums. These networks are prepared by crosslinking reactions of chlorine or tertiary amine-containing polymers with ditertiary amines and dihalide compounds, respectively. Degradable and de-cross-linkable polymers are an important category of polymeric materials that can be converted to small molecules or low-MW polymeric species after fulfilling the designed applications.
